The present disclosure is related to a driving technology for liquid crystal display, in particular, related to a source driver chip.
A driving circuit is an important portion in the industry link of liquid crystal display. The driving circuit, which is a critical device for the Thin Film Transistor-Liquid Crystal Display (hereinafter, TFT-LCD for short) module, takes a responsibility for turning on the thin film transistor and controlling the change in the arrangement of liquid crystal molecules. In the field of TFT-LCD driver, there still exist some problems to be improved, for example, the source driver chip of TFT-LCD has the technical defects as follows.
On the one hand, at data signal output terminal, the number of data signal output channel which can be maximally provided by the source driver chip is of a certainty, such as 720 channels, while the number of one row of sub-pixels in the display area of liquid crystal display is not always an integer times of the number of data signal output channels which can be maximally provided. Therefore, the data signal output channels in some source driver chips are in idle without being utilized. Moreover, an operational amplifier is disposed as a buffer in the data signal output channel. When the data signal output channel is normally utilized, the operational amplifier can be used to output the data signal normally, and when the data signal output channel is in idle, the operational amplifier is also left idle instead of being utilized, thus resulting in a waste of the operational amplifier in idle data signal output channel.
On the other hand, at input terminal of a reference voltage signal such as Gamma voltage, while two redundant operational amplifiers which can be used for the drive of the reference voltage, are incorporated into the source driver chip in the prior art, the connection has to be made through the external circuit, which increases the number of the external wires and is relatively complicated. Therefore, the amount of the redundant operational amplifiers is limited, and the resources in the internal space of the source driver chip can not be sufficiently utilized. In addition, since the extremely small resistors connected in parallel are required for the reference voltage circuit of peripheral driving circuit so as to decrease the influence on reference voltage by the internal Gamma resistors of source driver chip, this results in an increment in power consumption of the peripheral driving circuit.